body{
	background-color:gray;
	text-align:center;
	max-width:900px;
	margin:0px auto;
}
header,footer{
	background-color:orange;
	color:white;
	text-align:center;
}
header{
	padding:30px;
	margin-top:20px;
}
header h1{
	font-size:40px;
	margin:0px;
}
/*<div id="container">的内部样式设置*/
#container{
	background-color:white;
}
section{
	width:60%;
	padding:30px;
	margin:auto;
}
article{
	background-color:#eee;
	padding:10px;
}
article header,article footer{
	padding:5px;
}
article h1{
	font-size:18px;
}
select,button{
	margin:10px;
	font-size:16px;
}
footer{
	padding:15px;
}
footer h2{
	font-size:14px;
}